Babies with Older Autistic Siblings Are Less Able to Pick Up Language Clues, Study Shows

Most babies are able to look at adults’ mouths when they’re speaking and pick up clues about how language is formed. The more time infants spend watching people speak, the better they understand spoken language as toddlers.

However, researchers have discovered that something different tends to happen in the cases of infants who have older autistic siblings. These babies still pay close attention to adults’ mouths during speech, but they don’t seem to glean the same benefits from that careful observation.

“Attention is not enough,” says Hannah Feiner, lead investigator and fellow at Yale University. “There’s some downstream component [of language development] that we have to be researching and targeting and assessing.”

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For the study, researchers recruited 90 12-month-old babies with a neurotypical older sibling and 61 12-month-old babies with an autistic sibling. They tracked the infants’ gazes during a video of an actor speaking while surrounded by toys. They then calculated how much time babies spent looking at the screen and how much time they spent looking at the speaker’s face and mouth.

Researchers also tested each baby’s expressive and receptive language skills at the beginning f the study and again at 18 months using the Mullen Scales of Early Learning.

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Both sets of babies, researchers found, spent roughly the same amount of time watching the speaker’s face. However, the infants with autistic siblings had worse language skills at 18 months than the control group did. For the controls, spending more time looking at the speaker’s face was correlated with better language skills, but the same correlation did not exist for the babies with older siblings on the autism spectrum.

In other words, babies with autistic siblings appear to observe but not internalize the linguistic clues that help young children learn to understand and speak a language.

Photo: Adobe Stock/New Africa

“Attention feeds learning,” says Katarzyna Chawarska, co-investigator and professor of child psychiatry at Yale University. “But attention in and of itself does not guarantee that the information about the stimuli — their structure, their value — is going to be abstracted, remembered and used.”

The team believes their results suggest that babies with autistic siblings are more likely to display traits of autism as well. These young children may require extra support to help them build language skills and other abilities.

Feiner presented the findings virtually at the 2021 International Society for Autism Research. She and the rest of the team hope their work leads to tailored language interventions for children who are at an increased risk of autism.

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